An IC-card having an IC memory is known as a card having an information storage function. Recently, a non-contact IC-card has been in practical use as a prepaid card for use of ski lifts or the like. Such an IC-card includes an IC chip incorporated in a card member made of a synthetic resin. More particularly, the IC-card comprises an IC module which is incorporated in a card member made of a synthetic resin and having a predetermined thickness, and the IC-card module comprises an electronic circuit including an IC memory and an antenna coil.
The antenna coil not only provides its inherent function as an antenna for transmitting and receiving radio waves but also has a function of supplying a drive power to the IC chip by inductively generating an electromotive force upon receiving radio waves. Therefore, an IC-card incorporating an antenna coil can eliminate the need for incorporating a power source. Such an IC-card requires a further thickness reduction.
A conventional antenna coil utilizes a wire-wound coil formed of a metal wire. The wire-wound coil has a structure in which the metal wire is wound about 50 turns, for example, so that it has a large thickness. If the number of wire turns is reduced in order to reduce the thickness of the wire-wound coil, the properties of the antenna may be degraded. Consequently, the wire-wound coil becomes inevitably bulky, and there is a limitation on the thickness reduction of an IC-card. Further, in manufacturing the IC-card, the wire-wound coil and the IC chip, prepared separately, need to be aligned with each other, and the ends of the wire-wound coil must be connected to the electrodes of the IC chip in such a manner that they do not positionally deviate relative to each other. Accordingly, the series of the manufacturing steps is very complicated to result in a poor production efficiency. Furthermore, the wire-wound coil is liable to disconnection when the IC-card is deformed under bending for example.